With so much great technology on the market these days, it’s easier than ever to record conversations, whether over a landline, mobile phone, or even in person with a hidden recording device.

Recorded conversations (either on tape or digital) are often very useful in a variety of settings. These audio recordings can help in an investigation of employee misconduct or in business or personal lawsuits, including potential criminal investigations.

However, it is very important to ensure that any recording, whether of a telephone conversation or an in-person conversation, complies with federal and state laws. Failure to do so may very well expose you to criminal charges or civil lawsuits. And it is unlikely that you can legally use the recording for its original purpose.

So if you’re thinking about recording a few phone calls or putting a voice-activated recorder in a room to record conversations, you’ll need to check the applicable laws.

The first place to look is the federal wiretapping statute, also known as the Electronic Communications Privacy Act. Federal law allows telephone calls (traditional, cellular, and wireless) and other electronic communications to be recorded with the consent of at least one party to the conversation.

This means that if you are one of the people participating in the conversation, it can be recorded because one person (you) has consented to the recording. If you do not participate in the conversation, at least one of the people in the conversation must be aware of and consent to the recording.

However, you cannot stop after considering federal law and assuming that your recording passes the test. Each state and territory has its own statutes regarding the recording of conversations. Most state wiretapping and wiretapping laws are based on federal law and allow recording with the consent of one party to the conversation.

The 37 states that allow the recording of consent to a portion of oral communications are: Alaska, Arkansas, Colorado, Georgia, Hawaii, Idaho, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, West Virginia, Wisconsin and Wyoming.

The District of Columbia also allows individuals to record conversations with the consent of a single party. Nevada has a one-party consent statute, but there is some question about how courts should interpret the law. It could be considered a state of consent of all parties.

The 12 states that definitely require all parties to a conversation to consent before it can be recorded are: California, Connecticut, Delaware, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, New Hampshire, Pennsylvania, and Washington.

In California, there is an exception. You can record a conversation with the consent of only one party if it involves certain criminal activity (kidnapping, extortion, bribery, or a violent felony).

Therefore, the basic rule is that it is illegal to record conversations or communications in which you do not participate, unless you have the consent of at least one, if not all, of the participants.

The obvious exception to this general rule is that law enforcement officials may seek permission from a court to conduct wiretaps without consent as part of a criminal investigation. For the finer points of your own state’s laws and requirements, you should always consult with an attorney.